why cant two equipotential suface intrsect?why electric line of force must always be perpendicular to th surface?

1. If two equipotential surfaces did intersect, then there would be two values of potential at the point of intersection. However, this is not possible. Therefore, two equipotential surfaces CANNOT intersect.

2. Consider that electric lines of force have a component that is not perpendicular to the surface. Such a component would bring about movement of charges on the surface, which would result in a surface current. However, electric fields are due to static charges and hence surface currents would be against electrostatics. Thus, electric lines of force must always be perpendicular to the surface.